1. Field of the Invention
This invention relates to switch actuators for centrifugal switches, and more particularly to an actuator lever assembly which eliminates the need for readjustment after assembly and can be used in automatic laundry appliances.
2. Description of the Prior Art
Switches which make and break electrical contacts in response to the rotational velocity of a motor are known in the art. Mechanisms mounted on the motor shaft having elements which are moved away from the shaft due to the centrifugal force generated by rotation of the shaft are known as centrifugal mechanisms. Such mechanisms are utilized to operate circuit control switches, known as centrifugal switches, as shown in representative U.S. Pat. Nos. 4,095,073, 3,699,288, 2,991,655 and 2,747,854.
Such centrifugal switches have wide application, including use in domestic appliances such as an automatic clothes dryer. The manner of use and operation of a centrifugal switch in a dryer appliance control is described in U.S. Pat. No. 4,112,588.
Centrifugal switches have in common a centrifugal mechanism mounted on the motor shaft which is movable in response to the rotational velocity of the shaft, and switch contacts spaced from the shaft which are movable by an actuator linking the rotational velocity-responsive element to the contacts. A problem arising in the assembly of such switches within the machinery to be controlled thereby is that of consistently achieving proper dimensional location of the stationary switch actuator relative to the rotational velocity-responsive element of the centrifugal switch mechanism. Improper or imprecise location of one relative to the other results in such problems as incorrect switch cutout speeds, failure of the centrifugal mechanism to actuate the stationary switch, and rubbing of the actuator against the rotational velocity-responsive element during motor operation. Previous solutions to this problem all involve manual readjustment or reworking of some portion of the switch mechanism, such as relocating the velocity-responsive element on the motor shaft, bending the actuator, or repositioning the stationary switch or adjusting the stationary switch position.
The nature of the adjustment which must be made is a result of typical manufacturing variations in the tooling of the individual parts of the mechanism, which may result even if each part is manufactured within specified tolerances. The previous solutions to the problem all involve the addition of more personnel and/or assembly steps to the assembly process, thereby increasing the time and cost of assembly.